HARLEM — Inspector Rodney Harrison believes he knows who stood on the scaffolding above a basketball court at 129th Street and Adam Clayton Powell Jr. Boulevard and fired the shells from a Mossberg shotgun that killed Ackeem Green, 25.
But the alleged killer in the June 3 incident, where three other people where shot, including two who were hit in the head, remains at-large because no one is willing to formally identify him, said Harrison, commander of the 32nd Precinct.
"We do know who the perpetrator is," he said.
"The problem now is getting cooperation."
Harrison was expressing his frustration during a meeting with community groups organized by Harlem Councilwoman Inez Dickens and attended by Council Speaker Christine Quinn last week.
"Everybody knows who did the shooting," he added. "What we need to put this individual behind bars is for someone to say 'I saw the shooting' and testify."
Police believe the incident was a gang-related retaliation for an earlier beating of a member of the "Goodfellas" or "New Dons" who were shooting at members of the "Good Money Boys," or GMB, who were on the court.
Green, a young father, is not thought to have been the intended target.
A "stop snitching" culture where the idea of speaking with police to help them solve crime is strongly discouraged and even reinforced with threats of violence is blamed by Harrison for letting the killer roam free.
There have been 17 shooting incidents in the 32nd Precinct in 2012, but only five arrests so far, said Harrison.
The 32nd Precinct is also leading all Harlem precincts in homicides, with seven murders through July 22 compared to four last year, a 75 percent increase.
The "stop snitching" culture is a problem Harrison said he deals with on a regular basis.
"We are not getting a lot of cooperation," said Harrison.
After a shooting at the Entertainers Basketball Classic at Rucker Park where five people were hurt, Harrison admitted to threatening to shut down the tournament unless witnesses came forward to identify the alleged shooter.
"There had to be 1,100 people at that tournament, but I had to twist the organizer's arm, I had to threaten to shut them down to get them to cooperate," said Harrison.
Ricardo Laing, of White Plains, was arrested and charged with five counts of attempted murder for that shooting which police believe was sparked over an argument or heckling. Video of the incident shows the crowd running in fear.
The tournament was supposed to restart last Monday, but Harrison temporarily shut it down. Police Commissioner Raymond Kelly said the issue was about security, but both Harrison and tournament founder and organizer Greg Marius said otherwise.
Marius said that police were pressing him to get witnesses to cooperate, a power he felt he didn't have. But after he threatened to shut the tournament down, people came forward, said Harrison.
"No one wants to see anything? No more tournament," he said to nods of approval at the meeting.
Gregory Collins, 48, who served as a mentor to Green and who dated his mother, said the news that the police believe they know who committed the shooting but haven't been able to make an arrest is disheartening.
"I'm still losing sleep that those individuals who pulled the trigger on those people are still in the street," said Collins, founder of the Harlem Youth Marines of which Green was a member.
He said he and the Harlem Youth Marines were trying to gather reward money to entice someone to come forward.
"Every day I think of what happened to Ackeem and I want justice," said Collins.
"I don't want to get so angry that I want revenge, but these young men are free walking the street and they need to pay the consequences."
Both the alleged shooter and the community remains in danger as long as he remains on the street, said Iesha Sekou of Street Corner Resources.
"The shooter is on the street and will shoot again because he now has the mentality that he can get away with it," said Sekou. "And the weapon is still out on the street."
Young men from rival gangs will also want to take revenge on the person they think is the alleged shooter, said Dickens.
"The kids begin to feel like 'I'm going to take care of it,'" she said.
Harrison said the night of the Rucker Park shooting he shifted officers from Rucker Park to 129th Street to deal with another issue. Marius said there were only two officers at the park the night of the shooting, several fewer than usual.
"That day we were shorthanded and we had to deploy cops to 129th Street," said Harrison. "We had to rob Peter to pay Paul, and Peter had the incident."
Some in the audience said the lack of willingness to cooperate with police has to do with controversial police tactics such as stop-and-frisk, which critics say doesn't get guns off the street and only creates animosity in the communities where police need help to solve violent crimes.
Kelly and Mayor Michael Bloomberg have credited the tactic with record drops in crime.
Harrison called for a system that offered higher rewards for information and that allowed more people to testify while concealing their identities.
"In order for me to be successful, I need to hear what's going on in your streets," Harrison told the crowd.
For Collins, every day without an arrest grows more difficult.
"The way things are now, that means they got away with it," he said.
"Are we going to wait until they kill someone else? I wish somebody would step up."